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TitleGeology of the Dubawnt Lake area, Nunavut-Northwest Territories
AuthorPeterson, T D
SourceGeological Survey of Canada, Bulletin no. 580, 2006, 56 pages; 1 CD-ROM,
PublisherNatural Resources Canada
MapsPublication contains 1 map
Map Info.geological, bedrock geology, 1:100,000
Mediapaper; CD-ROM; digital; on-line
RelatedThis publication contains Peterson, T D; (2002). Geology, Dubawnt Lake area, Nunavut-Northwest Territories, Geological Survey of Canada, "A" Series Map no. 2021A
File formatreadme / lisez-moi
File formatpdf (Adobe Acrobat Reader v.6.0 is included / est fourni); txt
ProvinceNunavut; Northwest Territories
NTS65K/13; 65K/14; 65K/15; 65L/16; 65M/01; 65N/02; 65N/03; 65N/04; 65N/05; 65N/06; 65N/07; 65N/10
AreaDubawnt Lake; Round Island; Lost Boat Island; Dumb-Bell Island; Dubawnt River; Mosquito Lake; Nicholson Lake; Long Island; Peanut Island; Grant Lake
Lat/Long WENS-102.5000 -100.5000 63.7500 62.7500
Subjectsregional geology; structural geology; stratigraphy; igneous and metamorphic petrology; tectonics; geochemistry; bedrock geology; structural features; correlations; lithology; petrography; Archean; Aphebian; igneous rocks; intrusive rocks; diorites; granites; monzonites; granodiorites; leucogranites; peridotites; diabase dykes; volcanic rocks; basalts; felsic lavas; lava flows; tuffs; rhyolites; breccias; lamprophyres; megabreccias; volcaniclastics; metamorphic rocks; gneisses; schists; quartzites; metapsammites; amphibolites; orthogneisses; paragneisses; greenschist-amphibolite facies; sedimentary rocks; dolostones; conglomerates; sandstones; siltstones; iron formations; faults; shear zones; unconformities; bedding; foliation; lineations; domes; radiometric dates; zircon dates; uranium lead dates; aeromagnetic interpretation; anomalies; imbrication; red beds; rhyodacites; sands; gravels; fluvial deposits; alluvial deposits; geological history; tectonic history; tectonic setting; plate tectonics; metamorphism; deformation; mylonitization; basins; paleocurrents; crustal uplift; grabens; volcanism; magmatism; magma differentiation; erosion; weathering; deposition; plutons; dykes; emplacement; orogenesis; minettes; olivine; phlogopite; amphibole; clinopyroxene; spinel; feldspar; leucite; isotope geochemistry; strontium; neodymium; rubidium-strontium ratios; whole rock analyses; whole rock geochemistry; rock analyses, rare earth elements; x-ray fluorescence analyses; rock analyses, trace elements; mantle; Mackenzie diabase dykes; Dubawnt Supergroup; Barrensland Group; Lookout Point Formation; Kuungmi Formation; Thelon Formation; Wharton Group; Nueltin Suite; Nueltin Granites; Nueltin basaltic dykes; Pitz Formation; Baker Lake Group; Kunwak Formation; Christopher Island Formation; Hudson intrusions; Amer Group; Snow Island Suite; Clarke River Schist; Snow River Gneiss; Dubawnt Basin; Kamilukuak Basin; Churchill Province; Snowbird Tectonic Zone; Dubawnt minette dyke swarm; Thelon Basin; Superior Province; Slave Province; Trans-Hudson Orogen; Outlet Bay volcanic field; MacDonald Fault; Bathurst Fault; Thelon Tectonic Zone; extension; collisions; indentation; electron microprobe analyses; mantle xenocrysts; inductively coupled plasma optical emission spectroscopy; Phanerozoic; Cenozoic; Quaternary; Precambrian; Proterozoic
Illustrationsaerial photographs; sketch maps; tables; photographs; magnetic images; stratigraphic sections; stratigraphic correlations; photomicrographs; schematic diagrams; rose diagrams; schematic cross-sections; plots; geochemical profiles
LinksMetadata - Métadonnées
LinksGSC Map 2021A / Carte CGC 2021A
Released2006 06 01
AbstractThe bedrock of the Dubawnt Lake area mainly consists of late Archean (2.6 Ga) granite to diorite plutons, which intruded schist and gneiss (greater than or equal to 2.7 Ga), all overlain by early Proterozoic (1.85-1.7 Ga) siliciclastic and volcanic rocks of the Dubawnt Supergroup. Granitic plutons were emplaced on the east side of the area at ca. 1.83 and 1.76 Ga.
The northwest-trending, leucocratic, and dominantly granitic Snow River gneiss is the oldest map unit. It is overlain by metapsammitic and schistose rocks with minor mafic volcanic rocks (Clarke River schist) which record at least one deformation event at upper amphibolite facies that predates 2.6 Ga. Both units were intruded by diorite, granodiorite, megacrystic monzonite, and leucogranite of the Snow Island suite, dated at 2.602-2.605 Ma.
Quartzite and minor siltstone, preserved as erosional remnants in a discontinuous northeast-trending belt, were deposited on Archean basement before 1.83 Ga, and are correlated with the Aphebian Amer Group. The quartzite units contain a shallowly southeast-plunging stretching lineation, formed during upper greenschist- to lower amphibolite-facies metamorphism, which predates the Dubawnt Supergroup.
The lowermost Dubawnt Supergroup (basal Christopher Island Formation) consists of minor immature sandstone and conglomerate, and extensive flows of felsic, potassic lavas that were erupted directly onto Archean/Aphebian basement. These were transected by narrow strike-slip and normal fault valleys that were filled with mafic to felsic ultrapotassic volcanic and volcaniclastic rocks, overlain by fluvial/alluvial siliciclastic deposits of the Kunwak Formation. Ultrapotassic volcanism was probably synchronous with the emplacement of granitoid plutons of the Hudson suite (ca. 1.83 Ga) within the Snow River gneiss domain. A felsic minette flow yielded a zircon U-Pb age of 1833 ± 3 Ga, and volcanism was probably synchronous with the emplacement of Hudson granitoid plutons within the Snow River gneiss domain.
At ca. 1.75 Ga, the eastern side of the map area was intruded by rapakivi granite (Nueltin granite). Minor rhyolite domes of the correlative Pitz Formation (middle Dubawnt Supergroup) are preserved. A period of erosion and intense chemical weathering was followed by deposition of flat-lying conglomerate and sandstone of the Thelon Formation (upper Dubawnt Supergroup) at about 1.72 Ga; a major depocentre lay to the west, under the present Thelon basin. The youngest event recognized is the emplacement of northwest-trending diabase dykes of the Mackenzie swarm at 1.72 Ga.